The transition from college student or stay-at-home mom to full-time professional requires a number of changes. Those changes include updating your wardrobe to give it a more professional feel. Clothing that's acceptable for a jaunt to the store or a night out may not be appropriate for the office.

Just what constitutes a professional wardrobe has changed over the years, and the guidelines for such attire are no longer as firm as they once were. But it still behooves a woman to add some classic, professional pieces to her closet. While skirts and pantyhose may no longer be mandatory, dressing conservatively and cleanly in an office environment is always a safe bet.

In order to achieve a wardrobe transformation without breaking the bank, the fashion experts at Marie Claire advise adding separates to build around a base suit. Find a suit that is flattering to your figure and make it a workplace staple. Then purchase coordinating pants, sweater sets, shirts, another skirt, and accessories that can be mixed and matched with elements from the suit to create different looks. If your budget allows, purchase another suit in a different color so you can continue to build wardrobe possibilities.

When selecting base pieces, opt for neutral colors of tan, gray, black, and blue so that these items can be worn repeatedly without being noticed. Accessories and blouses can offer pops of color when necessary. A nice handbag or pair of shoes can quite easily add color to an otherwise monotone ensemble.

When selecting items from the rack, look for those that fit well but aren't too constrictive or racy. Inquire with your new employer's hiring manager or human resources department to find out if the workplace has any restrictions on wardrobe. There may be employee guidelines, particularly in certain industries, such as law or education. If no such restrictions are in place, keep skirts to knee-length and avoid particularly low-cut tops. Save more revealing items for nights out with friends.

Many employers have adopted dress-down days as perks for their employees. Although you may be invited to dress more casually, avoid dressing for a day at the beach or hanging around the house. Opt for trouser-style jeans that are free of rips and embellishments. If athletic shoes are allowed, make sure they are clean and not the pair you wear while tending to your garden. Avoid graphic T-shirts that feature potentially offensive or suggestive messages. In more conservative companies, dressing down may be opting for khakis instead of suits. It is important to know the difference.

Women who are adding to their wardrobes can include these all-time business staples.

• Classic black pump shoes

• Crisp, button-down white shirt

• Fine-knit sweater in a bright color

• Camisole or shell in a neutral color to wear under blazers

• Cardigan in black or white that can be worn over tops or dresses

• Fitted, sleeveless dress that can be paired with a suit jacket or cardigan

• Straight-hemmed skirt in a neutral color

• Flat-front black, gray and tan pants

• Neutral-colored wool coat and a rain jacket

Over time, women can add to their wardrobes as budgets allow and they learn more about what is acceptable at their places of hire.